[RFC PATCH bpf-next 0/3] bpf, x64: Fix tailcall hierarchy

[Leon Hwang <hffilwlqm@gmail.com>]

This patchset fixes a tailcall hierarchy issue.

The issue is confirmed in the discussions of "bpf, x64: Fix tailcall infinite
loop"[0].

For resolving details, please read the next patch.

Currently, I only resolve this issue on x86. The ones on arm64, s390x and
loongarch are waiting to be resolved too. So, the ci pipeline fails to run for
this issue fixing.

[0] https://lore.kernel.org/bpf/6203dd01-789d-f02c-5293-def4c1b18aef@gmail.com/

Leon Hwang (3):
  bpf, x64: Fix tailcall hierarchy
  bpf, x64: Load tail_call_cnt pointer
  selftests/bpf: Add testcases for tailcall hierarchy fixing

 arch/x86/net/bpf_jit_comp.c                   | 136 ++++---
 .../selftests/bpf/prog_tests/tailcalls.c      | 384 ++++++++++++++++++
 .../bpf/progs/tailcall_bpf2bpf_hierarchy1.c   |  34 ++
 .../bpf/progs/tailcall_bpf2bpf_hierarchy2.c   |  55 +++
 .../bpf/progs/tailcall_bpf2bpf_hierarchy3.c   |  46 +++
 5 files changed, 603 insertions(+), 52 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy1.c
 create mode 100644 tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy2.c
 create mode 100644 tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy3.c


base-commit: 2e7e9faf9a5d46788bf7a4d07c6c1caf57367d23
-- 
2.41.0